


The Law of Large Numbers

by Apostrophic



Category: The X-Files
Genre: Birthday Cake, Domestic Fluff, Established Relationship, F/M, Friendship/Love, Parenthood, Post-Season/Series 09 AU
Language: English
Status: Completed
Published: 2018-02-05
Updated: 2018-02-05
Packaged: 2019-03-13 20:03:50
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,192
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13577979
Author URL: https://archiveofourown.org/users/Apostrophic/pseuds/Apostrophic
Summary: “For Mom,” Mulder said, and the chunk he gave William was too big for her mouth. Scully caught most of it before it hit the floor, and William smacked caked hands together as Mulder kissed off the jello that smeared on her chin. “Mmm,” he said, and took seconds, and that’s how Scully wound up at the sink once the house had gone quiet, rubbing a William-sized splotch of strawberry-jello-stained cake off the front of her blouse.Let’s just take it for granted they get William back and live outside of Pittsburgh for a couple in-between years. This is when William turns three, and they’re still lying low, and a few milestones are celebrated. Including changing Mulder’s mind about strawberry cake. Post-season 9, AU.





	The Law of Large Numbers

**Author's Note:**

  * For [Lokisgame](https://archiveofourown.org/users/Lokisgame/gifts).



William turned three the year Scully turned forty. In February that year, the one birthday she wanted Mulder to forget, he remembered. They had found a small house in Wheeling, West Virginia, an hour outside of Pittsburgh, and were renting it by the month. Scully came home with groceries and found the kitchen doorway strewn with the lights they had put on the tree at Christmas. “Surprise!” Mulder said, obviously cueing William to say it like they had practiced, to which William gave a loud, tired hiccup and burst into tears. 

“No, no no,” Mulder said, bouncing William to calm him, which never worked when he was an hour past nap time. 

William didn’t hiccup his way down into soft, distressed sniffles until he was in Scully’s arms and she took him upstairs to put him down for a nap. “Bofog,” he said, and the bullfrog song worked. She left the door ajar, standing there for a moment to watch him clench and unclench his hands, his brow furrowed with sleep. 

“Surprise,” Mulder said, recreating the botched attempt when she found him back in the kitchen, putting the milk in the fridge. Scully grinned into his sweater when he pulled her close with one arm, planting a kiss in her hair. 

“Don’t leave the eggs out this time,” she requested, and he said okay, turning her first and pointing over the mantle. Thirteen pieces of paper were taped there, each with one letter, spelling out HAPPY BIRTHDAY. It might not bode well that she couldn’t tell which ones were Mulder’s and which ones were their son’s. 

“We left off the year,” Mulder said, coming up behind her, the eggs put away, to circle his arms around her waist. “You don’t look a day over thirty-nine and three-hundred-and-sixty-four days.”

“Gee thanks,” Scully said, almost preferring when Mulder talked about dog years or forgot altogether. 

Almost. 

Given the circumstances, her fortieth year was one she wasn’t sure she would reach. Not with a family intact, a two-year-old sleeping upstairs. She would take every one of those days and wear it as a badge of honor. 

“Your mom called,” Mulder said, disappearing back into the kitchen. “She said she’d call back later,” since calls placed to family were not a thing they risked often. Scully followed after him, watching him unsheathe a birthday cake from its plastic carton. It had strawberries on it, and the cake would be dry, but Maggie would call, catching Scully right before dinner, and the takeout would be good and the wine would be sweet, and William would make it through the birthday chorus that time. And later that night, once she was in bed, Mulder would slide over and say, “I forgot to give you my present,” and they would roll around in the bed and stifle bedsprings and laughter so as not to wake up their son, and, for that one day at least, forty was already an improvement over thirty-nine.  
  
  


* * *

  
  
William’s birthday was May. It rained for eight days leading up to it, until they were going stir crazy with cabin fever. The morning William turned three, the rain finally stopped. Mulder walked in their bedroom that morning, William tucked under one arm, and said, “Willie Nelson here wants to know what’s the plan for his birthday?”

“Mulder,” Scully said, “stop calling him that.”

“Willie Mays?” Mulder said. 

“William,” Scully said, addressing her son and ignoring his father, catching him when Mulder flew him over the bed and landed the ‘plane’ in her arms. William smacked the kiss back that she placed on his face. “Happy birthday, baby,” she said. 

“Birtday Mom,” he said, dropping the H’s he couldn’t say yet. 

“Do you want to go to the park for your birthday?”

“Yeeeeaaah,” Mulder cheered, next to them on the bed, trying to get William to say it. 

“Yeeeeeaaaah,” William said.

“I think that’s a yes, Mom,” Mulder said. 

“All right, you two,” Scully said, separating the troublemakers. William came with her, his little fists in a tight hug on her shoulders, babbling on about his birthday, as she got to her feet and shooed Mulder out of the room. “Your father,” she said, pulling a clean shirt down over William’s raised arms, “knows what he’s talking about. Let’s get you to the park before we all go crazy.”

William said “Yeeeaaah!” again and made a break for the door as she kissed his small head.  
  
  


* * *

  
  
Mulder sat on the bench, propped back on both arms, watching William crouch down and tear out handfuls of grass, dropping each clump on his shoes, frowning at the dirt and stray grass that stayed stuck to his hands. The picnic table was strewn with their lunch, what was left of ham and cheese sandwiches, lettuce and pickles. Scully sipped lemonade, watching Mulder watch William. 

“You think he’s figured out yet,” Mulder said eventually, “there are swings and a sandbox about ten feet behind him?”

Scully passed him her lemonade and Mulder took a long sip. “I think he knows,” she said. “I don’t think he cares.”

William never was one— not so far, anyway— for the usual playthings. He liked dirt, he liked bugs. The natural world. He’d leave a new toy and go play for an hour with one of Mulder’s old books, flipping through it one way, flipping back through it another. He’d take a crayon and scribble, his little brow furrowed, like someone needed his notes. “Just like his mother,” Mulder said now, watching him study the grass, and Scully smiled, tipping her face back, feeling the sun. 

They took a walk for a while, down by the river. The Ohio flowed past, swollen and churning with silt from the long week of rain. Mulder pointed at logs and William threw rocks where he pointed, each one falling short with an insignificant splash. They saw a boat and some birds. When William grew tired of walking, Mulder hoisted him up on his shoulders, and they stared across the river to the far shore. 

“That’s Ohio,” Scully told him, helping William say the word. It sounded more like _oreo._

“Where do we live?” she asked. 

“A house,” William said. 

Mulder had to laugh at the technically correct answer. He gave Scully a look. _Just like his mother, indeed._

“Yeah, a house,” Mulder said. “In West Virginia.”

William mimicked the words, getting ‘west’ right. 

“West Virginia is here.” Scully pointed down at their feet, and then back behind them. “Ohio is there.”

“It’s a whole different state,” Mulder explained, and William frowned, serious, as if the geography lesson wasn’t going over his head. 

He fell asleep on the ride home. Mulder took the long way, bumping down a few rural roads before they got to their own. There were scattered houses around, none too close or too far. No kids to invite for some cake at a party. Scully looked over at Mulder. “He’ll have to go to school soon. Meet other people. Make friends.”

Mulder nodded, looking out over the land that dropped away from the road and became a dense pack of trees. “We’ll figure it out,” he said, quiet, and drove.  
  
  


* * *

  
  
William blew out his candles, spitting all over the cake, missing the third one. Mulder huffed it out for him as Scully helped William cheer, holding him in her lap. She pulled out the candles, showing William how to lick off the whipped cream that was stuck on the wax, as Mulder sliced cake. It was white, topped with red, a layer of strawberry jello sitting atop the moist cake. Whipped cream in between. Summer cake, Scully called it, and the first time she made it, Mulder had stared at it, perplexed, like she had concocted something that required a case file. 

“It’s jello… on cake.”

“It’s delicious,” she said, which became a family debate. 

William loved it. He ate the cake with both hands, jello all over the table, bites too big for his fist, spreading his little fingers when the cake and whipped cream glommed there and stuck them together. “Here,” Scully said, handing him off to Mulder at the messiest part, going for a wet rag. She came back to find Mulder with cake in his own hands, feeding William a mouthful, then taking one for himself. Scully gave up as she watched them ruin their clothes. Mulder gestured her forward. 

“For Mom,” Mulder said, and the chunk he gave William was too big for her mouth. Scully caught most of it before it hit the floor, and William smacked caked hands together as Mulder kissed off the jello that smeared on her chin. “Mmm,” he said, and took seconds, and that’s how Scully wound up at the sink once the house had gone quiet, rubbing a William-sized splotch of strawberry-jello-stained cake off the front of her blouse. 

She had the table cleaned off by the time Mulder’s footsteps creaked back down the stairs. He found her there in the kitchen, dishes piled in the sink, the sink full of suds. He wore that tired-out, content look he wore often these days when he put William to bed. Scully sang to him; Mulder talked. She stood in the hallway sometimes, listening to the stories he made up, William loving them more than the ones in his books. Mulder took questions and answered each one of them patiently, dragging out bedtime for close to an hour sometimes. Until William was asleep in the chair and Scully had to come in to wake Mulder up, lifting William out of his arms to tuck him into his bed. 

Tonight, Mulder was tired, not asleep. Scully placed a dripping dish on the rack by the sink and picked up the next one to scrub with the sponge. What was left of the cake was in a heap on the counter and Mulder popped a bite in his mouth, licking whipped cream and jello off the end of his thumb. “Why’s that your favorite cake?” he asked, mouth half full, as if it had never occurred to him that he should ask her that question. William proved contagious. 

“I don’t know,” Scully said. She let a second dish drip. “My mom used to make it. She’d use my favorite jello, and pile strawberries on top. Thank you,” she said, mouth suddenly full with a strawberry Mulder put there. She ate it, swallowed, and said, “I remember Bill hated it.”

Mulder grinned. “Well, that’s reason enough,” he said, but the old rivalry had worn out, it was just something familiar and funny to say. 

“We’d have it on the Fourth of July,” Scully said. “And sometimes on my birthday, if we could find strawberries that time of year.” She smiled at the memory, sharing the smile with the sink as if it might smile back. 

“That’s nice,” Mulder said, something he usually didn’t say. He never tossed off a platitude, or used words like _nice_ unless it was something that wasn’t. But he said it sincerely, sounding quiet and wistful for mothers who made cakes and siblings who held strong opposing opinions. 

“It was,” Scully said. She amended, “It is.” She took the bite of cake Mulder gave her, this time a small bite and making no mess at all, and she savored it this time, tasting all the old flavors that William knew now. 

Mulder started to say something when they heard the phone ring. A sharp chirp with a buzz that made them both look around. It came from the chair by the door, tucked in Scully’s jacket where she had put it that day. Mulder crossed the cramped kitchen, grabbing the mobile phone. “It’s your mom,” he said quickly, holding it out to Scully before the ringing could stop.

Scully held up soapy hands. 

Mulder flicked the phone open. “Hi, Mrs. Scully,” he said, something that always amused the two Scullys, both younger and older. He would never call her mom Maggie, a fact they both tried to change and he firmly resisted. Then again, he hardly ever called her Dana… and her mom went right on blithely calling him Fox. “She’s right here,” he said now, and Scully shelved those family politics, leaning over to speak to the phone he held up to her ear. 

She dried off her hands when Mulder grabbed her the towel she had left out of reach. He relinquished the phone and she tucked it into her shoulder, telling Maggie about the park and the river, the strawberry cake, William’s adventures that day. “I… doubt it,” she said, and lowered the phone to pass along her mother’s question, asking Mulder if there would be any cake left by the time they saw Maggie that weekend. Mulder made an _oops_ face, another bite in his mouth. 

“I think what William left intact, Mulder’s demolished,” she reported. “I’ll tell him,” she said, after she listened a moment, and Mulder leaned down to say, “I’m sorry, Mrs. Scully,” into the mouthpiece as soon as his mouth wasn’t full. 

When Scully clicked off the phone several long minutes later, she surveyed the scene Mulder made, shaking her head at him. He’d cleared most of the counter, yes, putting up the stray things that accumulated that day, but that included ingesting several more strawberries and another wedge of the cake. He stood there now, picking through each layer, inspecting it thoroughly before it went in his mouth. “I’m glad you don’t like the jello,” Scully observed, morbidly impressed with his sweet tooth.

“It’s growing on me,” Mulder had to admit, forced into confession. Literally caught red-handed. 

Scully opened her mouth to tell him he could tell William why the cake was all gone and another half of a strawberry was popped into her mouth. 

“Mulder, stop that,” she said. Licking a dab of whipped cream that stuck on her lip. She clamped her mouth shut when Mulder tried it again, successfully fending him off. “You’re not making me culpable,” Scully informed him, and then looked down because Mulder simply smudged his icing-tipped finger above the neck of her blouse and leaned his face down to helpfully lick it off. 

“No,” Scully said sternly. “I’m not falling for that. I know all your tricks.”

“Oops,” Mulder said.

At the same time she said, “You can’t just do that and then tell me oops.” And then Scully sighed because an icing-tipped finger slid onto her tongue. 

Mulder was smiling, all the way up to his eyes. The day’s tiredness gone. His smile grew an inch wider as Scully returned his finger to him, licked thoroughly clean. 

“I mean it,” she said, sounding like she didn’t mean it at all.

She stopped to listen, and Mulder did too, making sure they didn’t hear William. 

“Coast is clear,” he reported, and slid his hands down her sides and around the small of her back as he pulled her into the kind of kiss that wasn’t playing at all. 

Scully was a little bit dizzy, her shirt a bit more degraded, by the time he let her go. She wrapped her knees around him when he set her down on the counter; as always, glad when she didn’t have to work so hard for his height. With his hands up her blouse, probably staining it pink, Scully kissed him again. She caught hold of his elbows, sliding her hands up his arms, then up and under his t-shirt. Returning the favor, making him good and senseless before she broke apart too. 

Something toppled behind her. It rolled; Mulder caught it before it dropped to the floor. It was the can of Readiwhip she’d used to make the cake topping. “Don’t you dare,” she said, warning, when Mulder shook the can vigorously, but all he did was tip his head back and fill his mouth with whipped cream. 

He already tasted like strawberries. Now he tasted like… well, a mouthful of whipped cream and sugar. She preferred when he tasted like dark things— coffee, dark chocolate, one of his rare malty beers— but this was good too. When the whipped cream was gone, Mulder interrupted the kiss to hold up the can again, shaking it. 

She trusted him this time. Scully opened her mouth, let him fill it with cream. “This is what I remember,” Mulder said, smiling, “about being a kid.”

“Had some interesting play dates, did you?” Scully said, forgetting her mouth was full. Mulder laughed, helped her out there, licking and kissing until all the whipped cream was gone. He topped it with a strawberry, doing that thing he loved doing, sliding fruit in her mouth. “Promise me something,” she said, as he dug about in the ruins of the jello for the rest of the berries. “When you do the whipped cream with William, you have to clean up the mess.”

“Promise,” he said, with jello all over his fingers. Scully sighed at the glob that fell in the neck of her blouse, this time truly on accident. She swiped it up herself, undoing two buttons to salvage what fabric she could. Mulder glanced down, watching this with a finger stuck in his mouth, and that did not help her keep caring about things like fabric. 

Scully sank her eyes closed, the put-upon sigh of being his partner. “Just _once,_ ” she bargained. But the burst of whipped cream was short and when she opened her eyes, it only topped the one strawberry that Mulder held out on offer.

That just made her smile, accept the offering warily. Mulder playing the long game was the most dangerous thing in her life. She decided to give him some rules, since he always loved those. She laid her wrist on his shoulder, slid her fingers into his hair, feeling lazy and generous. “We have a child in this house,” she said, watching Mulder find the next strawberry. “I think that means you can’t debauch me with fruit and whipped cream on the kitchen table.” 

Scully ate the next strawberry. Mulder’s grin was still in his eyes. “How do you think children get here?” he chided her gently. 

“Good,” Scully said, taking deflection from Mulder as tacit agreement. “So we agree, no debauching with whipped cream and strawberries on the kitchen table.”

Mulder repeated the rule carefully. “I won’t debauch _you_ with whipped cream and strawberries on the kitchen table.”

Oh, she had left that wide open. “No one’s debauching _anyone,_ ” Scully was quick to amend, but it was too late. Mulder latched onto that loophole. 

“You said no debauching _you,_ ” he said. “Rule number two: it’s perfectly fine if _you_ debauch _me_ on any surface you like with any fruit of your choosing.”

“Oh God,” Scully said, and took hold of his jaw and shook the can of whipped cream. She filled his mouth up to his grin, just to shut him up this time. 

He said something that sounded like “Thank you,” doing his best to swallow the whole mouthful at once, which should _not_ be erotic. Scully tried to clamp her mind down. “Right here,” Mulder said, voice muffled again somewhere inside his shirt, and then when it was gone he tapped at his bare chest. Dear God, he made her stupid. Her mind would not clamp down. 

She tried drawing a heart. The whipped cream sputtered and ended, colossally terrible timing. Half of the heart slid down. Oh well, Scully thought, sliding off the counter herself to chase it all the way down. She wound up at his stomach, and this proved more effective than a mouth full of whipped cream at shutting her partner up. 

They tossed the empty can in the sink. It was Mulder’s turn now to lean into the edge of the table. Scully pressed him back there. His lip turned strawberry-pink, and then red-jello-pink, when she nipped and bit him, always quick to add tongue, soothe it down with soft kisses. Scully kept his mouth occupied, Mulder more than compliant as she found the front of his jeans. 

“Uh-ho- _oh_ ,” was the sound that he made, part of his breath catching strands of her hair. Scully came up for air when she had him flat on the table, on her knees above him, Mulder’s hands in her back pockets, pulling her jeans against his. 

“We’re all out of whipped cream,” she said, and knew her hair looked sexed-up from the way Mulder’s eyes shone with joy. 

“Get creative,” he said, his voice scratchy and deep. 

Scully looked around for the plate. It was where Mulder left it, at the edge of her reach. She slid it an inch closer, swiped her thumb through the topping. When she touched it to his lips, Mulder slid his tongue out to taste it. The flush went through her whole body, a fact he could not miss. She had to be strawberry-pink. She shook her head, baffled, at the places she wound up with him. 

“Do that again,” Mulder told her. 

“Mulder,” she said, “You’re forty-two years old.” But she did it again. 

“That means I’m the answer to everything,” he said, and she had to remind herself they had not even been drinking. This was just how they talked when all his blood left his brain and all her blood rushed to hers. “Life, the universe, everything, Scully.”

_Hitchhiker’s Guide to The Galaxy._

“Huh,” Scully said, but lost that train of thought because she took the last strawberry and bit it between her teeth. Mulder wanted to kiss her with that in her mouth, but she kept her hand on his chest, holding him flat on the table. She savored the taste, fresh and delicious like summer, the heat that would soon be here after the spring rain was gone. The berry was tangy and sweet, both of the two things at once, caught in between, just like the two of them. 

Mulder would taste like it. Not just in his mouth, but all over his skin. She would take a long time to crawl back to his mouth, and by then she would not taste like strawberries, she would taste like something else. The salt taste of his body would replace the tangy, sweet fruit, the only taste in her mouth Mulder liked even more. 

They would climb up off the table. Mulder, long past ready, would not make it much past the sink. He would pin her there again, lift her hips up with his, her wet hands in his hair and his wet hands on her back as they held on and made love. The two of them in this together. Equal-share partners, in love with each other, stuck with a wrecked kitchen in a cramped, run-down house. 

The eight years of this, and then the three years that came after— Scully thought then— was not close to enough.  
  
  


* * *

  
  
Scully was forty and William was three when Mulder turned forty-three. It was October that year, the summer long gone and leaves falling off trees. They had begun to pack boxes, searching listings for places a little further south. This small house was untenable. Too cramped, too run-down. It had only ever been temporary while they figured out what to do. 

They made lists of what they wanted. A yard, Mulder said. Land. Schools, Scully said. She and William baked the cake that they covered with candles, and this time it was chocolate. 

At dinner that night, Mulder went around the table, reciting each of their ages for William to learn. “Forty,” he said, and pointed to Scully, smiling across at her. “Three,” he said, and pointed at William that time, helping him fold down a fourth finger so William had the count correct. 

And then Mulder tapped his own chest. “Forty-three,” he told William. When William asked why, Mulder said that’s because he was the sum of them both. 

Scully’s hand, a few minutes ago, had crossed to his side of the table, holding his palm in her own. She squeezed his hand now, which Mulder squeezed back, and she felt the same squeeze in her heart. The familiar fear for the future, the beauty of this one moment, the need to keep them both safe for the rest of her life. 

Mulder blew out his candles. He refused to tell them his wish, grabbing William and tickling when William tried to attack the cake first. He held William still, whispered something in his son’s ear, their dark heads bent together. “Tell Mom,” Mulder said. 

William tried hard to repeat it with all the words in the right order. Scully heard “lion birthday.”

“That’s right,” Mulder said. “What do you tell a lion on his birthday?”

Scully said, “I don’t know.”

William bounced in Mulder’s lap, throwing his hands up like claws, his whole face lit up. “Rooooaaarrr!”

Mulder was laughing. “No,” he said, “‘ _It’s roooooaaarrr birthday._ ’”

“Roooooaaaarrrr birthday!” said William, and Scully put her face in her hand, shaking her head at them both as William opened his mouth and Mulder ceremoniously stuffed it with the first bite of cake. 

**Author's Note:**

> Here were my rules from lokisgame: it had to have Scully’s red jello, William’s third birthday, Maggie and Fox, summer cake for dessert, whipped cream and strawberries, stained clothes in the kitchen, domestic duties like dishes, and lots of Dad Mulder, bonus points for dad jokes. 
> 
> And most important: no angst. You might die from something, but it won't be from angst.


End file.
